The present invention relates generally to the design of edge molded gaskets which are used to help seal an interface between two substantially flat surfaces. More particularly, the present invention relates to an integrated gasket wherein one portion is used for sealing a gear housing to the engine block interface and another portion is used for sealing a gear housing to the air compressor interface. A perforated score line separates the two gasket portions and this enables the air compressor portion to be separated from the engine block portion when only the air compressor has been accessed for service.
In a variety of diesel engine designs it is common for the interface between the gear housing and the engine block to be fitted with a sealing gasket, often a steel stamping. If the engine style includes an air compressor, the air compressor will typically be located adjacent to the engine block and will attach to the gear housing. It is typical for the interface between the gear housing and the air compressor to be fitted with a separate sealing gasket, often a steel stamping. With this particular arrangement involving two separate sealing gaskets, the gasket used between the air compressor and the gear housing can be replaced without having to replace the gasket disposed between the gear housing and the engine block. Accordingly, it is possible to separate the air compressor from the gear housing in order to work on the air compressor and when reassembling these two components, a new sealing gasket can be installed. The existing gasket positioned between the gear housing and the engine block is not disturbed. In view of the advantages of two separate gaskets as described, this approach has remained the standard in the industry.
If a single gasket is used for both interfaces, it would be necessary to either reuse the old gasket, which is not an acceptable practice, or disassemble the gear housing from the engine block and replace the entire gasket, even though the gasket portion disposed between the gear housing and the engine block does not need to be replaced for any other reason. By providing two separate sealing gaskets, the need or desire to replace one sealing gasket does not necessitate any change or replacement of the other sealing gasket.
To some extent the benefits of two separate sealing gaskets are offset by the fact that two separate stampings are required which means two sets of tooling to be created and maintained. Additionally, there are two separate components to be stocked and inventoried, and two separate components to be handled and assembled. These drawbacks can be lessened by going to one sealing gasket which combines or integrates the two sealing gasket portions. With one integrated sealing gasket, less tooling is required and there is less time required to install and position the gaskets at their corresponding interfaces between the two components which are being assembled.
The present invention uniquely provides the benefits of a single sealing gasket which is used for two interfaces with the advantages of two separate sealing gaskets. According to the present invention, a single-piece, steel stamping is fabricated with the required size and shape for sealing the interface between the gear housing and engine block as well as for sealing the interface between the gear housing and an air compressor. A perforated score line partitions the stamping into a first gasket portion for the first interface and a second gasket portion for the second interface. By bending the second portion back and forth along the perforated score line (i.e., work hardening), the second portion which seals the air compressor interface is able to be separated from the first gasket portion. As a consequence, the air compressor can be serviced and/or repaired without having to disassemble the gear housing from the engine block. Upon reassembly of the air compressor to the gear housing, a new separate sealing gasket is used.
Over the years, various patents have been issued on gaskets and gasket systems for a variety of uses and applications, including internal combustion engines. The following listed patents are believed to provide a representative sampling of such earlier patents:
______________________________________ PATENT NO. PATENTEE ISSUE DATE ______________________________________ 5,022,833 Kandpal et al. Jun. 11, 1991 4,676,514 Beutter et al. Jun. 30, 1987 5,343,837 Ward et al. Sep. 6, 1994 4,690,413 Adkins Sep. 1, 1987 5,433,455 Nelson Jul. 18, 1995 ______________________________________
Since the listed patents are representative of earlier gasket designs, it is important to note that the present invention is neither anticipated nor rendered obvious by any of the listed patents.